Haptoglobin: a review of the major allele frequencies worldwide and their association with diseases

Abstract

Summary Haptoglobin (Hp) is a plasma α2‐glycoprotein which binds free haemoglobin, thus preventing oxidative damage. The complex is rapidly removed from the circulation by a specific receptor (CD163) found on macrophages. Three major subtypes, Hp1‐1, Hp2‐1 and Hp2‐2 are the product of two closely related genes HP1 and HP2. The frequency of the HP1 and HP2 genes varies worldwide depending on racial origin: the HP1frequency varying from about 0.07 in parts of India to over 0.7 in parts of West Africa and South America. Both HP1 and HP2 have been linked to susceptibility to various diseases. Such associations may be explained by functional differences between the subtypes in the binding of Hb and its rate of clearance from the plasma. However, there are also corresponding negative reports for disease associations. The conflicting evidence on disease association and the lack of association between disease and particular populations, despite the wide range of HP1 and HP2 gene frequencies across the world, may indicate that any associations are marginal.

Differential expression of haptoglobin isoforms in chronic active hepatitis, cirrhosis and HCC related to HBV infection

“…These phenotypes are correlated to susceptibility to various diseases ranging from heart and infectious diseases to cancer. The HP serum level varies among different phenotypes, since the lowest amount is present in HP 2-2 and the highest in HP 1-1 patients (18). Notably, evidence reveals specific profiles of HP-α chain in sera from breast, ovary and head and neck cancers (15,17,19).…”

Identification of genetic variants influencing the human plasma proteome

“…None of our top SNPs were analyzed in those studies, but the most significant SNP in the eQTL analyses by Zeller et al (15) is rs6499560, an SNP that is also associated with the peptide levels in our data (P value = 2.92 × 10 −13 ). Haptoglobin is an Alpha-2-glycoprotein that binds free hemoglobin and protects tissues from oxidative damage and has been associated with a large number of disease states, including cardiovascular diseases, diabetes, cancer, and persistence of various infections (17), as well as regulation of serum lipid levels (2,18). Two different polymorphisms in the HP gene have been suggested to play an important role in protein activity.…”

Under Increased Hydrogen Peroxide conditions, the Antioxidant Effects of Pequi Oil (Caryocar brasiliense Camb.) to Decrease DNA Damage in Runners are Influenced by Sex, Age and oxidative Stress-related Genetic Polymorphisms

“…Because GPx-scavenger of nitric oxide (NO), a free radical vital in basal blood flow regulation and vascular homeostasis, regulating NO bioavailability and vascular homeostasis. [18] Several functional differences reported between Hp phenotypes could have important biological and clinical consequences. These differences are explained by a phenotype-dependent modulation of oxidative stress and prostaglandin synthesis.…”

“…Moreover, the ability of the serum glycoprotein haptoglobin (Hp) to block hemoglobininduced oxidative stress and damage is reportedly phenotype dependent. [18] Since the prudent recommendation for physically active individuals is a diet rich in antioxidants from natural foods, [10] natural antioxidant supplementation can prevent exercise-induced damage in athletes who exercise strenuously and exceed their endogenous antioxidant defenses [9] or even for those who were born less genetically favored by the antioxidant defense system. In previous studies, our group demonstrated that carotenoid-rich oil from pequi (Caryocar brasiliense Camb.…”